“…Since the 1990s, MERLO has been a pedagogy and teaching technique developed, validated and experimented with within different countries and across different content areas and disciplines (Etkind, Shafrir, Kenett, & Roytman, 2016;Etkind & Shafrir, 2013;Etkind et al, 2010). As a pedagogical tool, MERLO is appropriate for different versions of core content based on sharing the meaning across different forms of representation (Arzarello et al, 2015;Robutti et al, 2016, 2020a, Robutti, Prodromou, & Aldon, 2020b. Additionally, MERLO is a powerful tool for problem-solving mathematical concepts known as duplication obstacles, extensive in all mathematics classrooms.…”